Fig. 3

Reverse genetic screen reveals zebrafish il34 as a regulator of microglia development. (A) Accumulated data from all gRNA injections showing the number of NR⁺microglia as quantified with SpotNGlia. Magenta bars represent genes showing a significant reduction in microglia numbers upon CRISPR/Cas9-based targeting (black bar, control; green bars, genes with non-significant reduction in microglia numbers). (B) NR⁺ microglia numbers in 3 dpf zebrafish larvae injected with gRNA-Cas9 RNPs targeting il34. Controls in A and B are non-injected WT larvae. (C) A −5 bp deletion in exon 1 of il34 directly introduces a stop codon. (D) NR⁺microglia numbers in il34 mutants with a premature stop codon in exon 5 and their heterozygous and WT siblings at 3 dpf. (E) GFP⁺ microglia in the optic tecti (dashed lines) of 3 dpf il34 mutants and controls, and quantification of their numbers and the fraction of microglia containing more than one protrusion (ramified microglia). Controls in D and E are WT (il34^+/+) larvae. *P<0.05, **P<0.01, ***P<0.001. One-way ANOVA and Student's t-test. Bonferroni correction for multiple testing. Scale bars: 100 µm. Each dot represents one larva. Error bars represent s.d.